1. Filed of Invention
Aspects of the invention can relate to a package for an electronic component, and especially to a package for an electronic component having a plurality of mounting electrodes for connecting to connection electrodes of the component itself contained in the package and to a method of manufacturing a piezoelectric device.
2. Description of Related Art
Related art piezoelectric devices, such as quartz resonators or quartz oscillators, as electronic components are contained in surface-mount type packages having main bodies formed with ceramic to have box-shapes in order to meet requirements of smaller-sized or thinner electronic instruments. The piezoelectric devices having such box-shaped packages are often handled with wrong orientations in, for example, right and left direction. And it can be inconvenient that the piezoelectric devices do not normally function when they are mounted with wrong orientations in right and left direction. Therefore, as described in FIGS. 19(1) through 19(3), a related art piezoelectric device can be equipped with a pair of terminal for operating the piezoelectric resonator element, which is disposed on both edges of a diagonal of the bottom of its package body so as to be mounted without any considerations on its mounting orientation. See, for example, Japanese Unexamined Patent Publication No. 11-214950. Note that, FIG. 19(1) shows a plan view with its cover omitted, FIG. 19(2) shows a cross-sectional view thereof with the cover along the A—A line, and FIG. 19(3) shows an arrow view along the B—B line of FIG. 19(2).
In FIGS. 19(1) through 19(3), the piezoelectric resonator 10, which is one of the piezoelectric devices, has a piezoelectric resonator element 14 (a component body) contained inside a package 12. The package 12 is composed of a package body 16 formed like a box with ceramic and a metallic cover 19 for sealing the inside of the package body 16 airtight.
The piezoelectric resonator element 14 can be composed of, for example, a piezoelectric plate element 15, such as an AT-cut quartz plate, excitation electrodes 18a, 18b (the excitation electrode 18b is not shown in the drawings) are provided in the center and on the both sides of the piezoelectric plate element 15. Further, the piezoelectric resonator element 14 can include a pair of connection electrodes 20 (20a, 20b) on one edge thereof in a longitudinal direction. Each of the connection electrodes 20 can be formed continuously on both surfaces of the piezoelectric resonator element 14 and electrically connected to respective one of the excitation electrodes 18a, 18b. And, the excitation electrodes 18 and the connection electrodes 20 are formed symmetrically on the both surfaces of the piezoelectric resonator element 14.
On the bottom of the package body 16, there can be formed a pair of mounting electrodes 22 (22a, 22b) correspondingly to the connection electrodes 20. As shown in FIG. 19(2), these mounting electrodes 22 are provided with the corresponding connection electrodes 20 fixed via electrically conductive adhesive 24 to electrically connect the mounting electrodes 22 with the excitation electrodes 18. Further, the package body 16 can include external terminals 26 (26a through 26d) for connecting to a mounting board not shown at respective corners of the outer surfaces of the bottom.
One mounting electrode 22a in the package 12 is electrically connected to the external terminal 26a via a through hole not shown or the like. Further, the other mounting electrodes 22b can be electrically connected to the external terminal 26c via a connection wiring section 28 shown in FIG. 19(1). Therefore, the pair of electrodes of the piezoelectric resonator element 14 is electrically connected to the external terminals 26a, 26c positioned on a diagonal of the package 12. And, the other pair of external terminals 26b, 26d is connected to the ground of the board and is electrically connected to the cover 19. Thus, the cover 19 can be held in the ground potential to electromagnetically shield the inside of the package 12.